A gate valve of this kind is known from U.S. Pat. No. 2,934,313. The gate valve shown here has a four-part housing with a housing bottom part, on which a housing cover is fixed with bolts. On two sides facing each other, the housing bottom part and the housing cover form circular openings, each having a thread. A pipe body with a mating thread can be screwed onto each of the two threads. All four parts form a flow pipe. The flow cross-section of this pipe can be closed by a sliding element, which can be lowered from the housing cover transversal to the flow direction of the flow pipe. For sealing the touch areas between the housing parts and the contact areas between the sliding element and the housing, the gate valve has a scaling insert made of rubber. The sealing insert has a tubular shape. Inside the sealing insert, the flow cross-section is substantially limited by metal rings, which are inserted in the sealing insert. The metal rings serve the purpose of keeping the flow cross-section inside the sealing insert clear.
U.S. Pat No. 5,279,320 shows a gate valve with a sliding element, which has a groove on each side. When opening and closing the gate valve, the sliding element will be guided via the grooves through corresponding tracks on the gate valve housing. The sliding element has a plastic-coated core. In the area of the grooves, the coating of the core is made of a hard polymer material to reduce the friction. In the remaining areas, in which the sliding element bears on the housing in the closed state, the coating consists of a soft polymer material. This ensures a good sealing.
DE 43 25 192 A1 shows a disk gate valve. Here, an assembly and disassembly in the movement direction of the gate valve is possible. For this purpose, the disk gate valve has a sliding housing, which is divided into a housing top part and a housing bottom part. A sealing lining with a circular opening is built into the sliding housing. When a replacement of the sealing lining is required, the housing top part can now be removed from the housing bottom part together with the sealing lining. Subsequently, the sealing lining on the housing top part can be replaced. Further, the sealing lining has a separate cross sealing, which can be removed separately from the remaining sealing lining when disassembling the disk gate valve.
In operation, for example in utility water systems, gate valves must ensure a reliable closing for a relatively long life (up to 50 years).